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From: Lorenzo Bettini (bettini_at_[hidden])
Date: 2005-06-07 01:50:28
Eric Niebler wrote:
> 2) Grab tracking_ptr.hpp from
> boost-sandbox/boost/xpressive/detail/utility (can also be found in
> xpressive.zip from the Boost Sandbox File Vault).
>
> I had to solve the same problem for xpressive, where regex objects can
> embed other regex objects, either "by value" or "by reference". This
> leads to all sorts of interesting cyclic ref-count scenarios. I use
> tracking_ptr to handle this.
indeed also my context has to do with regular expressions and mutual
cyclic ref-count scenarios (in source-highlight
http://www.gnu.org/software/src-highlite). As I said in a response to a
previous post, I solved the problem by storing weak pointers in the
cyclic structures and store a shared pointer into a list that is kept
alive for all the life of the cyclic structures.
>
> Unfortunately, tracking_ptr is not documented. I forces you to separate
> your object into a handle-body, where the body inherits from
> enable_reference_tracking<Body>, and the handle holds a
> tracking_ptr<Body>. There's more, but maybe you can figure out the rest
> by seeing how xpressive uses tracking_ptr.
OK, thanks!
Lore
-- +-----------------------------------------------------+ | Lorenzo Bettini ICQ# lbetto, 16080134 | | PhD in Computer Science | | Dip. Sistemi e Informatica, Univ. di Firenze | | Florence - Italy (GNU/Linux User # 158233) | | Home Page : http://www.lorenzobettini.it | | http://music.dsi.unifi.it XKlaim language | | http://www.lorenzobettini.it/purple Cover Band | | http://www.gnu.org/software/src-highlite | | http://www.gnu.org/software/gengetopt | | http://www.lorenzobettini.it/software/gengen | | http://www.lorenzobettini.it/software/doublecpp | +-----------------------------------------------------+
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